413: COST ANALYSIS OF EMPIRIC COVERAGE FOR PATIENTS WITH MDR GRAM-NEGATIVE INFECTIONS

Abstract

Introduction: Gram-negative resistance to empiric antibiotic therapy has been associated with increased mortality rate, prolonged hospital length of stay and increase cost. The objective of this study is to compare total hospital costs associated with the appropriate and inappropriate empiric antibiotic therapy for critically ill patients with documented Gram-negative infections. Methods: Single-center, retrospective, cohort study conducted at a tertiary academic medical center. Data was collected from the electronic medical record for patients admitted from January 2015 to December 2017. Patients ≥18 years of age with culture-positive Gram-negative infection during the first 2 days of admission and started on antibiotics were included. Appropriate empiric coverage was defined as antibiotics with microbiological activity against the organism subsequently isolated in cultures within 24 hours collection. The primary outcome was the total hospital costs (fixed and variable) for the entire hospital stay. Descriptive statistics were performed and Mann-Whitney U, Fisher’s exact test, and χ-square test were conducted, where appropriate. Results: 832 patients were included in this study with 79 (9.5%) of the patients characterized as receiving inappropriate empiric antibiotics. There were no differences between patients receiving appropriate and inappropriate empiric therapy. Hospital and ICU length of stay were also statistically similar. There were significantly lower pharmacy costs incurred in patents receiving appropriate empiric therapy compared to inappropriate ($1,893 [3,319] vs. $2,252 [5,629], p=0.016). Total hospital costs incurred by patients receiving appropriate empiric therapy were numerically lower ($20,848 [30,377] vs. $23,006 [39,222], p=0.052). Conclusions: Inappropriate empiric antibiotics for patients with culture-positive Gram-negative infections was associated with significant increase in overall pharmacy cost and charges and numerically greater total hospital cost and charges.